The concerns, which have been simmering for months, have taken on new urgency as the Commerce Department considers adopting a sweeping proposal that would allow the United States to block transactions between American firms and Chinese counterparts. Those rules, on top of new restrictions on Chinese investment in the United States and proposed measures that would prevent American companies from exporting certain products and sharing technology with foreign nationals, have the tech industry scrambling to respond.

The Trump administration’s crackdown has already prompted foreign firms to shun American components and technology over concerns that access to parts they need could be abruptly cut off. American companies are watching warily as the United States considers restricting export licenses for companies that sell products or share intellectual property with China, including General Electric, which sells aircraft parts to China as part of a joint venture with Safran, a French firm…

There is growing bipartisan consensus in Washington that China poses a security threat and that the United States must protect domestic industries to retain a technological edge. But the tech industry has warned that limiting access to China, both in terms of selling and buying products, could cripple American companies and end up undercutting the United States as the biggest global hub of research and development.